Contaminant: Coliform Bacteria (Including E.Coli)
Private wells should be tested annually for the presence of Coliform bacteria. Total Coliform bacteria are a group of microorganisms. If a test for Coliform bacteria is positive, then E. Coli (Escherichia Coliform) and/or Fecal Coliform tests can be performed on the water sample. If a Total Coliform test is positive, the occupants should stop drinking the water until the problem is remedied. Bringing the water to a full boil for 3 minutes before drinking or cooking, or using bottled water is a temporary solution. Symptoms include nausea and diarrhea. These can occur shortly after drinking contaminated water. The effects could be short-term yet severe (similar to food poisoning) or might recur frequently or develop slowly over a long time.
Fecal Coliform and E. Coli: Fecal Coliform and E.Coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Disease causing microbes or pathogens in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special risk for infants, young children, and those with compromised immune systems.
Bacterial contamination can result from a number of sources. Human and animal wastes are a primary source of bacteria in water. These sources of bacterial contamination include runoff from feedlots, pastures, dog runs, and other land areas where animal wastes are deposited. Additional sources include seepage or discharge form septic tanks and sewage treatment facilities. Insects, rodents or animals entering the well are other sources of contamination. Another way bacteria can enter a water supply is through inundation or infiltration by flood waters or by surface runoff. Flood waters commonly contain high levels of bacteria. Any system with casings or caps that are not water-tight, or lacking a grout seal in the annular space, are vulnerable.
The EPA establishes standards for drinking water which fall into two categories – Primary Standards and Secondary Standards.
Primary Standards are based on health considerations, and are designed to protect people from three classes of toxic pollutants; pathogens, radioactive elements and toxic chemicals. Bacterial contamination falls under the category of pathogens. The EPA Maximum Contaminant Level (MCL) for coliform bacteria in drinking water is zero (or no) total coliform per 100ml of water.
You can read about symptoms from Drinking Coliform Bacteria in Water here. (Livestrong.com)
Coliform Treatment: Ultra Violet Disinfection System (UV Light)
Ultraviolet water purification is a unique and rapid method of water disinfection without the use of heat or chemicals and does not alter the taste of the water. The water enters the purifier and any bacteria in the water are exposed to UV light from the germicidal UV lamp. UV light disinfects by penetrating microorganisms and disrupting their DNA, preventing them from multiplying. A microorganism which cannot breed is of no concern. Water leaving the purifier is instantly ready for use. Some municipalities require the use of special UV systems which will disable the water to the home if a malfunction occurs or if the annual lamp change is ignored.
To disinfect water, experts recommend that Ultraviolet (UV) systems should be among the first options to consider because it is effective and versatile. UV technology destroys about 99.9% of all pathogens in the water. Other benefits of UV treatment include the fact that no chemicals or byproducts are being introduced into the water supply, while it is still effective for disinfection of water by removing cysts, bacteria, and viruses.
Note: There is a form of temporary treatment for bacteria. A temporary treatment effort would be the possible disinfection of the well with a chlorine “shock”. “Shocking” the well with chlorine may remove the bacteria, but Coliform is known to be a recurring problem. Periodic chlorine shocking and/or multiple attempts may be needed to disinfect the well. All chlorine must be out of the water system before a retest can be taken. RAdata does not perform chlorine well “shocks” because of the low success rate and high probability for the bacteria problem to return.